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United States Patent |
5,211,561
|
Graub
|
May 18, 1993
|
Coupling device for dental prothesis
Abstract
A coupling for removable dental protheses comprising a male member one end
of which is constituted by a fixing member, whereas the other end has the
shape of a male coupling member and a female portion comprising a rigid
casing fixed into the prothesis which houses a resiliently deformable mass
provided with a housing intended to receive the male coupling member of
the male portion. This resiliently deformable mass is maintained in the
casing by a removable ring clipped on the casing so that the replacement
of this mass is effected without any intervention on the prothesis. In one
embodiment, the male coupling member is a cylinder connecting through a
rib to a support and the female portion of the coupling comprises a
cylindrical sleeve of resiliently deformable material maintained within
the casing of the female portion of the coupling by a slotted ring, the
ring comprising locking formations cooperating with corresponding
formations of the casing and of the sleeve and fixing its angular service
position with respect to these two parts. In another embodiment, the male
coupling member is a sphere and the rigid casing is non-spherical, the
resiliently deformable mass having a spherical cavity that receives and
retains the sphere. The removable ring contacts and retains the
resiliently deformable mass but is spaced from the male member.
Inventors:
|
Graub; M. Walter (Twann, CH)
|
Assignee:
|
Metaux Precieux sa Metalor (Neuchatel, CH)
|
Appl. No.:
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887399 |
Filed:
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May 21, 1992 |
Foreign Application Priority Data
Current U.S. Class: |
433/169; 433/172; 433/181 |
Intern'l Class: |
A61C 013/28 |
Field of Search: |
433/169,172,181,182
|
References Cited
U.S. Patent Documents
1665154 | Mar., 1928 | Withycombe | 433/169.
|
4362509 | Dec., 1982 | Sulc | 433/169.
|
4547156 | Oct., 1985 | Hader | 433/172.
|
5098295 | May., 1992 | Durr et al. | 433/169.
|
Foreign Patent Documents |
0298909 | Jan., 1989 | EP.
| |
1104365 | Jan., 1960 | FR.
| |
597843 | Apr., 1978 | CH.
| |
646046 | Nov., 1984 | CH.
| |
646047 | Nov., 1984 | CH.
| |
650662 | Aug., 1985 | CH.
| |
651194 | Sep., 1985 | CH.
| |
651462 | Sep., 1985 | CH.
| |
674926 | Aug., 1990 | CH.
| |
WO87/06816 | Nov., 1987 | WO.
| |
Primary Examiner: Wilson; John J.
Claims
I claim:
1. In a coupling for removable dental protheses comprising a male member
one end of which is constituted by a fixing member, whereas the other end
has the shape of a male coupling member and a female portion comprising a
rigid casing fixed into the prothesis which houses a resiliently
deformable mass provided with a housing intended to receive the male
coupling member of the male portion; the improvement wherein this
resiliently deformable mass is maintained in the casing by a removable
ring clipped on the casing so that the replacement of this mass is
effected without any intervention on the prothesis in which the said
casing is fixed, the male coupling member being a cylinder connecting
through a rib to a support and the female portion of the coupling
comprises a cylindrical sleeve of resiliently deformable material
maintained within the casing of the female portion of the coupling by
means of a slotted ring, the ring comprising locking formations
cooperating with corresponding formations of the casing and of the sleeve
and fixing its angular service position with respect to these two parts.
2. Coupling according to claim 1, wherein the retention force of the
coupling is determined by the friction forces existing between the sleeve
and the cylinder.
3. In a coupling for removable dental protheses comprising a male member
one end of which is constituted by a fixing member, whereas the other end
has the shape of a male coupling member and a female portion comprising a
rigid casing fixed into the prothesis which houses a resiliently
deformable mass provided with a housing intended to receive the male
coupling member of the male portion; the improvement wherein the male
coupling member is a sphere and said rigid casing is non-spherical, said
resiliently deformable mass having a spherical cavity that receives and
retains said sphere, and a removable ring clipped on the casing and
contacting and retaining the resiliently deformable mass but spaced from
said male member.
Description
BACKGROUND OF THE INVENTION
There are numerous existing systems for removable dental protheses making
generally use of couplings of the press-button type one part of which,
usually the male part, is fastened onto the jaw of the patient either in
the bone or in a valid tooth, and the other part of which, the female
part, is fastened in the prothesis. Such coupling devices are for example
described in the following patents CH 646.046; CH 646.047; CH 651.462 and
CH 651.194.
Most of these devices have the drawback of a too rigid fixing of the
prothesis in the mouth, so that under the effect of shocks and efforts due
to chewing of the food stuff, it is frequent that after a certain duration
the cementing of the male part implanted into a valid tooth or into the
jaw bone is loosened or destroyed.
In the device described in the patent CH 597.843 a fixing rider which is
elastically deformable is put between the male and female part of the
coupling giving a certain smoothness to the fixing of the prothesis.
However, during the setting in place and the withdrawal of this prothesis,
the resilient deformation of this rider transmits substantial forces to
the prothesis. These forces make it necessary to provide important and
very solid walls of the prothesis to avoid its deterioration and this
increases the weight and the encumbrance of the prothesis in the mouth.
There are further other types of coupling permitting a removable fixing of
a prothesis with a certain degree of smoothness which use male or female
coupling members made in two parts which are resiliently deformable the
one with respect to the other. The drawback of these devices is that the
voids and spaces comprised between these two parts fill with detritus or
tartar causing a bad hygiene of the mouth and a bad working of the
coupling device.
Patent CH 674.926 discloses a coupling for removable dental prothesis which
comprises a retention member which is fixed in the mouth, one end of which
is formed by a threaded rod whereas the other has the shape of a portion
of a sphere and a matrix comprising a rigid casing housing a resiliently
deformable mass provided with a void intended to receive this spherical
portion of the retention member. This matrix presents means for a rigid
and definitive fixation into a prothesis.
The drawback of this type of coupling resides mainly in the fact that the
resiliently deformable mass is rapidly weared off and that its
characteristics are modified with the aging within the mouth.
SUMMARY OF THE INVENTION
The present invention has for its object a coupling for removable dental
prothese of the type of the one described in the patent CH 674.926, but
which, eliminates its major drawback. The coupling for removable dental
prothesis distinguishes itself by the fact that the resiliently deformable
mass is maintained in the casing through a removable ring clipped or
snapped onto the said casing so that the replacement of this mass is
effected without any intervention on the prothesis in which the housing is
fixed.
BRIEF DESCRIPTION OF THE DRAWINGS
The attached drawings show schematically and by way of example two
embodiments of the coupling device for a removable dental prothesis.
FIG. 1 shows in elevation a male portion of the coupling and in
cross-section the female portion of said coupling, in coupled position, of
a first embodiment of the coupling.
FIG. 2 shows in perspective view a retention ring of the female portion of
the coupling shown in FIG. 1.
FIG. 3 shows in perspective view the male portion of a second embodiment of
the coupling.
FIG. 4 shows in perspective view the female part of the second embodiment
of the coupling.
FIG. 5 shows in perspective view a third embodiment of the female part of
the coupling.
FIGS. 6 and 7 show constitutive parts of the female portion shown in FIG. 5
.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The first embodiment of the coupling device for removable dental protheses
shown in FIGS. 1 and 2 comprises a male portion 1 and a female portion 2.
The male portion 1 of the coupling has a threaded rod 3 at one of its ends
and at its other end a spherical part 4 connected to the threaded rod 3
through a polygonal zone 5 and a collar 6. The polygonal zone 5 is used as
a nut to screw the threaded rod 3 into a tooth, a root or the bone of the
jaw of the patient.
The female portion 2 of the coupling has a casing 7 comprising retaining
formations 8, here a circular groove, permitting the incorporation of the
casing into the molded mass of the dental prothesis, not shown. This
casing houses a mass made of synthetic deformable material 9 presenting a
spherical housing opening on the open face of the casing 7 through an
aperture 10 comprising a narrowing, of a diameter less than that of the
spherical housing. This spherical housing presents a diameter
corresponding to that of the spherical terminal portion 4 of the male
portion 1.
When the coupling is in service position FIG. 1, the spherical part 4 is
firmly maintained within the housing of the deformable mass 9.
This deformable mass 9 is maintained in service position within the casing
7 by means of a maintaining ring 11 made of synthetic material comprising
a circular extension 12 engaged in service position under the shoulder 13
of the outside wall of the casing 7. This ring comprises an annular
portion 14 firmly maintaining the deformable mass 9 within the casing in
service position.
The male and female portions 1, 3 of this coupling may be coupled and
uncoupled easily by introducing or pulling this spherical part 4 into or
out of the corresponding housing of the deformable mass 9, generally made
out of synthetic material, through resilient deformation of this mass. The
elasticity and/or the hardness of this resiliently deformable mass 9 are
calculated and adjusted in order to obtain the desired retention force.
A protecting ring, not shown, can rest on the collar 6 and the outside face
of the annular portion 14 of this ring 11 avoiding any obstruction of the
opening 10 by food stuff.
The interest of this solution resides in the fact that when the mass made
of resiliently deformable synthetic material, which is the only part of
the coupling which is able to wear off or to age, is worn out or deformed
by the normal working of the coupling it suffices to take the ring 11 and
this mass 9 out of the casing 7 and to introduce in said casing a new mass
9 generally maintained by a new ring 11 so that the coupling be renewed at
less cost without any intervention on the prothesis itself.
The second embodiment (FIGS. 3 and 4) of the coupling comprises a male
portion 1, comprising a support 15 intended to be cemented into a tooth of
the patient from which emerges a coupling member constituted by a cylinder
16 connected to the support 15 through a rib 17.
The female portion 2 of this coupling comprises a casing 18 intended to be
fixed rigidly, or incorporated into a removable dental prothesis having a
generally cylindrical shape presenting a central void and a lateral slot
19. A cylindrical sleeve 20 of synthetic deformable material is disposed
in the void of the casing and is maintained in service position through a
retention ring 21. This retention ring is slotted, its slot corresponds to
the one 19 of the casing 18, and comprises a clipping formation 22
cooperating with a corresponding formation of the casing 18.
The internal diameter of the sleeve 20 is less than or equal to the outside
diameter of the cylindrical part 16. The female portion 2 can thus be
introduced over the male portion 1, the rib 17 passing into the slot 19
and the cylinder 16 is being housed in the sleeve 20.
In this embodiment, the retention force between the two parts of the
coupling is obtained by the friction force between the sleeve 20 and the
cylinder 16.
Here also the sleeve 20 is easily interchangable, increasing without limit
the lifetime of such a coupling.
FIGS. 5 to 7 show a variant of the female part 2 of the coupling shown in
FIGS. 3 and 4 and its constitutive parts, the sleeve 20 and the removable
retention ring 21.
In this embodiment, the retention ring 21 comprises further locking
formations 23 cooperating in service position simultaneously with
corresponding formations 24 of the sleeve 20 and of the casing 18. Thus,
the angular service position of the sleeve 20 and of the ring 21 is fixed.
The evident and enormous advantage of this coupling for a removable dental
prothesis is to enable an unlimited use of the prothesis without harming
this delicate piece. The simple exchange or replacement of the resiliently
deformable mass 9, 20 enables renewing a worn out coupling.
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